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Tip of the Day
Language: Java
Expertise: Advanced
Nov 12, 2008

Make an Immutable Class

The following code shows how to make an immutable class:

package com.test;

final class TestImmutable
//	instance var are made private to restrict the access  
//	and final to not get reassigned

	private final int var1;
	private final double var2;

	public TestImmutable(int paramCount,double paramValue)
		var1= paramCount;
		var2 = paramValue;

//	Only accessors are provided i.e getters to access the variables

	public int getVar1()
		return var1;

	public double getVar2()
		return var2;

//class TestingImmutable
public class TestingImmutable
	public static void main(String[] args)
		TestImmutable obj1 = new TestImmutable(3,5);


		// There is no other way to change the values of var1 & var2
		//only accessors getVar1(),getVar2() to get the values 
		// no subclassing, no public access to varX
Devesh Gote
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